Sound-box.



W. N. DENNISON.'

SOUND-BOX. v

APPLICATION FILED JULY13,1908

978,566, Patented Deo. 13,1910.

UNITED. STATES PATENT onnicnf.

WILBUR-N DENNISON, OF M'RCHANTVILLE, NEWJERSEY, ASSIGNOR T0 VICTOR TALKING MACHINE COMPANY, A. CORPORATION 0F NEW JERSEY.

ASOUND-B0X.

Application flied July is, iao'. serial No. 443,290.

To all wheat 'it may concern: A

Beitl known that I, VVILBURN IN. DENNL i son, Aof the borough of Merchantville, county of Camden, and State of New Jersey, have invented certain new and useful Improveinentsin Sound-Boxes,- of which the followitig is a full, clear, and exact "description,

reference being had to the accompanying drawings, forming a part. of this .speditiontion: f

Th1 objects of my invention are to 'providev 'sound box casingof durable .forni consisting ot easily constructed'"parts, few

in number, and which 'may' be readily taken apart or assen'ibled; to provide a light and rigid stylus bar; tol provide a. ring or gasket for the diaphragmwhich is symin'etricaliu construction and which is securely seated within the casing: to' provide 'an improved forni 'of pneumatic ring or gasket for the mounting of the diaphragm and tomake provisions for inilating said gasket; ytio provide 'a torsional spring mounting for the stylus bar which restrains said har to oscillate in a plane perpendicular to and upon an axis substantially in the plane of the diaphragm, and to provide means-for the coiiveiiieut and accurate adjustment of the tension upon said spring; to provide ineansfor equalizing the cushioning effect of the atmosphere" upon the opposite'sides vofthe diaphragm and 'to prevent the loss of energy by the i lea-king of air past the diaphragm in order that the full effect of the action of the diaphragm uponv the air may be delivered amplifying means; and to provide other improvements as will appear hereinafter.

In the drawings, Figure -1 is a front ele` y. Fig. 2 a section on line 2-2 'of Fig. l; Fig.

"3 a fragmentary side elevation of the sound box ;`v Fig. 4 a section on line of 3, looking 11i the direction of the arrows; Figs. 5, 6, 7 a nd,.8.are enlarged perspective views of details of construction, and Fig." 9 is av sectional view' on' the' line 9 9 ofFig.

2 4and Fig. `10 shows modified forins hol- Y low stylus bars.

Referring to the drawings, one embodiment of this invention comprises a sound box casing having asubstantially cylindrical outer shell 1,`pro'vided with an inwardly eX-.

tending annular flange integral theiewith.

the casing,'and provided with an axially vcir- Y 'cular `opening 3 for, the admission of the inner end of a stylus har. The shell l has a cylindrical bore opening rearwardly, and having a rearwardly -.pen'ing annular internal recess 'forming an annular internal shoulder with the front portionof the bore andwitl:` 'i this recess snugly fits a removable baci-plate 4 forming'the rear end of the casing. This back plate 4 has an axial circnllariopening 5, .the diameterof theopening 3 in the front end'of the casing, and is provided in its edge with a longitudinal key-way 4 adapt. ed to be engagedby a key-5" rigid with the casing to prevent the plate from turning.

For attachii 0' the sound box 'tothe 'usual tubular soiiud ox arm or support., the rear face of the' end plate`4 of the sound box Vcasing has secured coanially thereto. by

of a; diameter equalV to means of screws 6, the usual tubular rubber Jannular shoulder of the casing, through the outlet of the soundbox to the AOppositely disposed .alnnular grooves 13. are provided upon the inner side oi the fre-nt end of the casing and upon the innerV side ofthe vrear e1iijl',of'-the casing, and are arranged coaxiall'ylwith tle casing to receive tubular/rubber rings or gaskets 14. respectively, Abetween` whichjis supported a dialiragin 15, the periphery ofthe diaphragm eing preferably spaced fromthe imita-'surf ,aces of the casing.

The gaskets are substantially circular in cross section, and are each'provided with an Iannular projecting rib 14 on the side of the gasket contacting I,with the diaphragm so that the vibrations of the diaphragm will not be affected by a varying surface contact with the gasket. The walls of the grooves 13 containing' the gaskets are substantially seinicircular in cross section and are adapted to' tit closely around the sides of the gaskets,

' to force the gaskets to deliver their full efiiciencies. l

' The gaskets 14 are preferably each constructed from a single piece of tubing, the

ends of'which may be brought together andjoined by a raw rubber or rubber cement, or a continuous rubber tube may be provlded with a rau" rubber portion as indicated at 14" and a pneumatic pump, similar to a' 1.5 is closed by the 'self-healingr act-ion'of raW` rubber or similar material, thus retalnmgthe pressure 'in thetube. This construction provides a .gasket which is-absolutely symu gmetrical with respect to the axis passing 2o 'through the center of the ring,.nor1nal to the p ane thereof and which will res`pond uniformly to 'the vibrations' ofl the diaphragm.

The whole mountingor supportforthe A diaphragm which,`in the'forrrltilli'ifstrated in' the drawings comprises the casing and the rings or gaskets*14,'forms, with the diaV phragm 1'5 anan'nular' Space I6 which incloses the periphery of the diaphram. This annular' space is preferably fillepwith av liquid, such. as water, -gl cerinqordilutedglycerin or other suitable 'qijd which may be.inif.= ctedbetween"tl1sda nemend 0110 of its "gaskets, oi" through the casinE after the sound box has been assemb ed, as through a suitable opening 16 in the casing, which may be afterward closedi'in any able manner as by a screwfl. This construction prevent-s losses of energy by the 40 escape of air from the-chamber on one side of the diaphragm to that on the other side thereof, and insures the deliveryof the full effect o f the act-ion of the diaphragm upon the air back-of the Same, to the amplifier.

The diaphragm is located substantially midway between the opposite inner surfaces of the ends of the casing, dividing the i n terior of the casing into two chambers, of

substantially equal capacity uponopposite4 sides respectively of the diaphragm which.

have, as heretofore 'pointed out axial openings or outlets of substantially equal area. By this means the cushioning effect of the air upo'n the opposite sides of the diaphragm 55 is substantially equalized. i' l The stylus bar comprises a light forging 17, 'formingr the lower or outer portion of the bar. This forging is provided adjacentits inner end, with a forwardly extending tubular lug v18 into which is forced or rigidly secured a tubular portion 19 extending substantially the entire distance between the axis of oscillation of the stylus bar and the diaphragm. The tulular portion 19 is preferably bent 1n any suitable manner, for 1nsuitrections from the stylus bar.

20 projecting from an enlarged portion 2O'- The head- 20 .of the bar engages against-the outersurface forming the head of the bar.

andto enter theopenof the. diaphragm and is clamped thereto bya screw 21 which passes through the dia-A phragm, and is threaded axial head of 'the bar, th'ehead 21 off the screw engagingv the'd-ia hragm upon its sidel o posite to' the hea of the bar, to clampt e diaphragm to the bar. l

To increase the rigidi-ty of the Styl-us bar, Y

the major part of the up er or i-nnerfpor-k y into" the tion 19 of the bar is pre erably made sub;

stantially oval or elliptical in crossgsecti'on,

its longer` diameter of the cross-section being substantially in the plane of oscillationA oi' the bar, as shown in Fig. 4; but the extreme upper end 193' and the extreme .lower I. end 192. on the upperv portion 19 ofthe bar are: preferably 'made cylindricalin l cross section to' facilitate. the, attachment' of the- ,same to the head 20 and the forging 17 respectively The lowerend of the stylus bar.

1s provided with' a ,longitudinal socket. 22

substantially Iin alinement with the plane of the diaphragm and with the axis of oscillation of the stylus bar, to receive theusual i stylus needle'23 which-ma be held in place by a set screw 24 thread'e .throughthelug 25 of the forging 17. l

For mounting the stylus bar, 'the upper end o f the forging is preferably formed as a substantially cylindrical sleeve or tubular portionf26 havin its longitudinal .axis substantially c oinci ent with the axis of oscillation ofthe stylus bar and'substantially` parallel to theplane of the diaphragm, the tubular portion projecting in opposite di'- within thesaid tubular portion 26 and substantially in alinement with the stylus socket 22 is a bushing or washer'27 which forms a rigid support for -the torsional springA 2S extending'therethrough and in opposite directions therefrom forming oppositely extending spring arms spaced from the inner surface of said tubular portion.

The bushing or washer 27 supporting the torsional spring 28 is preferably made of soft steel or brass,and after being positioned in the said tubular port-ion 26', is preferably compressed by oppositely 'disposed punches to upset the edges thereof to bring the pe.- riphery of th'e washer in very tight and rigid engagement with the inner surface'ot' the tubular portion 26 and the surface of the spring.

The spring 28 is preferably square, polygonal. irregular, or of an-.y other form than round in cross section to prevent the spring v' Centrally from turning in the bushing 27 and also so that the ends of the spring may be of suit` able shape to tit into the sockets 29 of the keys 30, by which the spring is adjusted and supported, and by which the desired tension is applied to said spring.

The keys 30 are cylindrical in shape and have reduced inner ends 31 containing thi sockets 29 and enlarged outer ends forming heads 32 which are'slotted as at 33 to receive a screwdriver for rotating the keys to adjust the stylus bar and bring torsional stress to bear upon the arms of the spring 28. The keys 30 are rotatably adjustable in the spaced split arms 34 which are rigid with the sound box casing, vand the keys are held in any desired fixed positions in the arms by means of theclamping screws 35 which extend through the splitI portions of the arms. The inner surfaces of the heads bear against the outer surfaces of the spaced arms and the inner ends of the keys bear lightly against the outer ends of the transverse tubular portion ofthe stylus bar thereby constraining the bar to oscillate on an axis parallel to the diaphragm.

In adjusting the stylus bar mounting the ends of the spring 2S are rotated in opposite directions from their normal posit-ions, by means of a screw driver acting upon the keys as heretofore stated, and the keys are then clamped into position by means of the clamping screws 35, so that the stylus bar is supported in its normal position, the

spring being held subject to a balanced,

initial torsional tension due to the positions of the keys, thus holding the ends of the spring securely in the keys, but leaving the spring free to respond to the slightest vibration of the stylus liar in a plane perpendicular to the diaphragm.'

By making the pivotal portion 17 of the stylus bar of a light forging, the walls of the sleeve 2G and of the lug and of the stylus socketmay be made very thin so that the whole stylus bar mounting, including the upper portion 1f), is substantially a hollow shell, very strong, butexceedingly lighti Although I have described a construction in which the upper partv 19 of tlif stylus is made hollow, I do not wish to be construed as limited to a strictly tubl'illar'form, or

fiattened tubular form for that part Aof the stylus bar extending between the point of oscillation of the stylus bar andthe diaphragm, inasmuch as a stylus bar, made hollow in any suitable manner, is fully within the aim and scope of my invention. Thus, I may make the upper part of the stylus bar hollow in a number of ways, as by making the same of pressed metal, or any other suitable material, stitfcned by webs, as shown in Fig. 10, and when'I employ the word hollow in the appended claims, I intend it to apply to all the forms like or similar to those illustrated in the drawings, whether the sectioi be of an open or closed form.

Although I have illustrated the various details of construction whereby all the objects above enun'ierated may be embodied in one sound box, it is obvious that many of the details may be separately applied to various kinds of sound boxes to great advantage. It is further obvious that my invention is capable of embodiment in many forms, without departing from thespirit of this invention or the scope of the appended claims.

Having thus fully described my-invcntion what I claim and desire to protect by Letters Patent of the United States is:

l. The combination with a diaphragm, of a pairof concentric yielding rings of substantially circular cross section having oppositely disposed circular ribs proj ccting therefrom engaging against the opposite sides of the diaphragm respectively.,l

2. A mounting for a diaph agm, comprising a yielding member having a body portion and a projection extending outwardly from said body portion and carried thereby to engage the diaphragm.

3. A mounting for a diaphragm, comprising a yielding member having a bodyvportion,. and an annular rib lprojecting outwardly from said body portion to engage the diaphragm.

4t. A gasket for a sound box, comprising a yielding tubular member having a rib projecting therefrom.

5. A gasket foi-"a sound box, comprising a yielding tubular member having a self healing portion through which the gasket may be inflated.

G. A gasket for a sound box, comprising a yieldingrtubular member having a portioncomposed of raw rubber.

7. A gasket for a sound box, con'xprising a pneumatic member having a rib projecting therefrom.

'8. In a sound box, the combination with a diaphragm, of a pneumatic gasket having a ribthereon in contact with the. diaphragm.

9. The combination with a diaphragm, of an inflated gasket contacting therewith for supporting 'the same, and having animperforatctubular main or body portion.

10. `In a sound box the combination with a diaphragm, of a mounting therefor forming with said diaphragm an inclosed space around the periphery of the diaphragn'i and means `within said space to prevent the passage of air therethrough.

11. In 'a sound box the combination with a casing, of a diaphragm, means to support said diajihragm in said easing, said means forming with said diaj'ihragm and said casing an annular space inelosing the periphery of the diaphragm and a liquid within said secured to said arms and engagin against said bar, and means to hold sai keys in.

space Yto prevent the passage of air therethrough.

12. In a sound box the combination with a diaphragm, of a mounting therefor form- Ving with the diaphragm a spacev inclosing the periphery of said diaphragm and a glycerin seal in said space.

13. -In a sound box, the combination with a diaphragm, of a mounting therefor, forming an inclosed space, and a liquid seal in said space.

14. The combination with a stylus bar, of a mounting therefor comprising a torsional spring secured to said bar, a key to turn said spring, said key having one end provided with a socket to receive the end -of said spring and its opposite endenlarged `to forni a head, and Imeans enga ing said lieand bearing against said hea .to hold said key in a xed position. A

15. A stylus vbar provided with a tubular portion extending axially thereof, a tor-v fixed positions.

18. The combination with a stylus bar, of a mounting therefor comprisin a tor sional spring secured to the bar ant having a portion otherwise than round in cross sec tion and a rotatably adjustable key engaging said angular portion to'hold the spring in position.

19. The-combination With a stylus bar, of a support therefor comprising a yielding member and a bushing surrounding said member and rengaging an internal seat provided therefor in said bar, said bushing' .being compressed into rigid engagement with said member and said seat.

20. The combination with a stylus bar, of a mounting therefor comprising a torsional spring secured to said bar, and rotatably adjustable means supporting said spring and for applying a torsional stress'to said spring.

21. The combination with a stylus bar, of.

a' mounting therefor' comprising a torsional spring having a portion of square cross section secured to said bar, and a rotatably adjustable key for engaging saidl portion.

22. The combination with a stylus bar, of mounting therefor comprising a torsional spring secured thereto, and rotatably adjustable means held against movement in one direction longitudinally of its axis While being rotated for holding said spring.

23. In a sound box, a stylus bar having a tubular portion, a spring support Within saidtubular portion and a spring passing therethrough, said parts being rigidly held together by the frictional contact between the same.

a stylus bar, of a spring square 1in cross section upon. which said stylus bar is mounted to oscillate, an adjustable key engaging an end of said spring, and means for holding said key in a fixed position.

25. The combination with a stylus bar, of a torsional spring upon which said stylus bar is mounted, the ends of said spring being of a shape other than round, and means provided with sockets Within which the ends of'said bar are fitted for applying a torsional stress to said spring.

2G. In a sound box the combination with a diaphragm, of a casing surrounding said diaphragm, said casing being provided with openings of substantially equal area upon opposite sides of the diaphragm respectively, a mounting for said diaphragm forming With said diaphragm an annular chamber, inclosing the periphery of said diaphragm, and means in said chamber to prevent the air from passing therethrough.

27. In a sound box the combination Wit-h a casing, of a diaphragm mounted therein, forming two chambers of substantially equal "capacity upon opposite sides respectively of the diaphragm, said casing having openings of substantially equal area into each of said chambers respectively, and a liquid seal to prevent the passage of air around said ldiaphragm from one of said chambers to the other.

Q8. In a sound box, a stylus bar mounted rto oscillate in a fixed plane, said bar having a hollow portion oblong in transverse section and with its longer transverse diameter ex- {eiiding in the plane of oscillation of said 29. In a sound box, a stylus bar havingahollow tapering upper portion oblon transverse section, extending' substantiallyl from the axis of oscillation of said stylus bar, to the upper end thereof. A

30. In a sound box, a stylus bar having a .transversely oblong tubular portion.

81. In a sound box, a stylus bar having a tubular inner end and `an engaging member forced into'said tubular end.

432. A sound box casing comprising a hol-l low shell having an internal rearwardly facing annular shoulder, a removable back plate resting in said shell against said shoulder, and a ring in said shell in the rear of said plate, for holding said plate in position.

24. In a' sound. box, the combination with l 33. A sound box casing comprising ahollow shell having an internal rearwardly facing annular shoulder, a' removable back plate resting in said shell against said shoulder, a ring in said shell in the rear of said plate, for holding said plate in position, and a diaphragm in said casing in front of said back plate, and a yielding` gasket between said diaphragm and said back plate, and in contact with said back plate.

34. A soundV box Casing comprising a hollow shell having an internal rearwardly facing shoulder, a. removable back plate fitting in said shell in the rear of said shoulder, and a ring in said shell in the rear of said back plate, for holding` said plate in position.

35. A sound box casing comprising a hollow shell provided with an open end, a plate fitting in said open end, a diaphragm in said casing inside of said plate, means rigid with said easing for limiting the movement' plate and held in position 'l of' said plate toward said diaphragm, yield ing means between said diaphragm and said by said plate,v and means for holding said Ward movement with respect to said easing.

36. A sound box casing comprising a holloW shell provided with an open end, a plate forming a closure for said open end, a diaphragm in said casing inside of said plate, means for limiting the movement of said plate toward said diaphragm, a yielding gasket between said diaphragm and said plate and held in position by said plate, and means for clamping'said plate against said gasket.

In witness whereof I have hereunto set my hand this eleventh day of J uly, 1908.

VILBURN N. DENN SON. `Vitnesses DEAN S. RENWICK, ROBERT H. CRaWroRn.

late against out- 

